Magnetic connector for electronic device

ABSTRACT

An electrical plug and receptacle relying on magnetic force from an electromagnet to maintain contact are disclosed. The plug and receptacle can be used as part of a power adapter for connecting an electronic device, such as a laptop computer, to a power supply. The plug includes electrical contacts, which are preferably biased toward corresponding contacts on the receptacle. The plug and receptacle each have a magnetic element. The magnetic element on one of the plug or receptacle can be a magnet or ferromagnetic material. The magnetic element on the other of the plug or receptacle is an electromagnet. When the plug and receptacle are brought into proximity, the magnetic attraction between the electromagnet magnet and its complement, whether another magnet or a ferromagnetic material, maintains the contacts in an electrically conductive relationship.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/028,195, filed Feb. 15, 2011, which is a continuation of U.S.application Ser. No. 12/581,010 filed Oct. 16, 2009, now U.S. Pat. No.7,901,216, which is a continuation of U.S. patent application Ser. No.12/410,457, filed Mar. 24, 2009, now U.S. Pat. No. 7,645,143, which is acontinuation of U.S. patent application Ser. No. 11/876,733, filed Oct.22, 2007, now U.S. Pat. No. 7,517,222, which is a continuation of U.S.patent application Ser. No. 11/235,875, filed Sep. 26, 2005, now U.S.Pat. No. 7,311,526, which are incorporated by reference.

FIELD OF THE DISCLOSURE

The subject matter of the present disclosure generally relates to amagnetic connector for an electronic device and more particularlyrelates to an electromagnetic connector for a power adapter connecting alaptop computer to a power supply.

BACKGROUND OF THE DISCLOSURE

Electronic devices, such as laptop computers, typically use DC powersupplied from a transformer connected to a conventional AC power supply.Referring to FIG. 1, a power adapter 20 according to the prior art isillustrated. The power adapter 20 has a transformer 22, a power cable26, a male connector 30, and a female connector 40. The transformer 22has a plug 24 for connecting to a conventional AC power outlet (notshown), and the male connector 30 is connected to the transformer 22 bypower cable 26. The female connector 40 is typically attached to thehousing 12 of an electronic device 10, such as a laptop computer, and istypically attached to a printed circuit board 14 of the internalelectronics of the device 10. To make the conventional power connectionbetween the transformer 22 and the device 10, the male connector 30 hasa male end 32 that inserts into the female connector 40. Connectors forportable computers are preferably as small as possible and low profilefor today's thin notebooks.

Damage can occur to the conventional power connection in a number ofways. In one example, simply inserting the male connector 30 into thefemale connector 40 can cause damage. In another example shown in FIG.2, damage can occur when any of the components (e.g., the device 10,male connector 30, transformer 22, etc.) is inadvertently pulled awayfrom other components by a non-axial force while the male and femaleconnectors 30 and 40 are still connected together. In addition toconventional power connections, damage of other types of connections toelectronic devices can also occur in the same ways described above.

In general, the surface area of two magnetically attracted halvesdetermines the number of magnetic flux lines and therefore the holdingforce between them because the holding force is proportional to thecontact area between the two magnetically attracted halves. Thus, tohave a strong force holding the two magnetically attracted halvestogether, the two magnetically attracted halves want to be as large aspossible.

The subject matter of the present disclosure is directed to overcoming,or at least reducing the effects of, one or more of the problems setforth above.

SUMMARY OF THE DISCLOSURE

A magnetic connector that relies on magnetic force for maintainingcontact is disclosed. The magnetic connector includes a plug and areceptacle. In one embodiment, the plug and receptacle can be used aspart of a power adapter for connecting an electronic device, such as alaptop computer, to a transformer connectable to a power supply. Theplug includes a plurality of electrical pins, which are preferablybiased towards a corresponding plurality of contacts positioned on thereceptacle. The plug and receptacle each have a magnetic element. Themagnetic element on one or both of the plug and receptacle can be amagnet, which is preferably a permanent rare earth magnet althoughelectromagnets may also be used. A ferromagnetic element can be used forthe magnetic element on the plug or receptacle that does not include amagnet. When the plug and receptacle are brought into proximity, themagnetic attraction between the magnet and its complement, whetheranother magnet or a ferromagnetic material, magnetically couples theplug and the receptacle and maintains the pins and contacts in anelectrically conductive relationship. The magnetic connector allows theplug to break away from the receptacle if the plug or receptacle isinadvertently moved (with sufficient force) while still connected.

The foregoing summary is not intended to summarize each potentialembodiment or every aspect of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, preferred embodiments, and other aspects ofsubject matter of the present disclosure will be best understood withreference to a detailed description of specific embodiments, whichfollows, when read in conjunction with the accompanying drawings, inwhich:

FIG. 1 illustrates a power adapter having a power connection accordingto the prior art.

FIG. 2 illustrates a type of possible damage resulting from the priorart power connection.

FIG. 3 illustrates a cross-sectional view of an embodiment of a magneticconnector according to certain teachings of the present disclosure.

FIG. 4 illustrates a front view of a receptacle of the magneticconnector of FIG. 3.

FIG. 5 illustrates a front view of a plug of the magnetic connector ofFIG. 3.

FIG. 6 illustrates an ability of the disclosed magnetic connector toprevent possible damage.

FIG. 7 illustrates an alternative embodiment of the magnetic connectorof FIG. 3.

FIGS. 8A-8B illustrate a plug of another embodiment of a magneticconnector according to certain teachings of the present disclosure.

FIGS. 9A-9B illustrate a receptacle for the plug of the disclosedmagnetic connector of FIGS. 8A-8B.

FIG. 10 illustrates a perspective view of the plug and receptacle forthe disclosed magnetic connector of FIGS. 8A-8B and 9A-9B.

FIGS. 11A-11B illustrate an embodiment of a magnetic connector accordingto certain teachings of the present disclosure having a plurality ofmagnets and a back plate.

FIGS. 12A-12B illustrate another embodiment of a magnetic connectoraccording to certain teachings of the present disclosure having aplurality of magnets and a back plate.

FIGS. 13A-13B illustrate embodiments of magnetic connectors according tocertain teachings of the present disclosure having electromagnets.

FIG. 14 illustrates an embodiment of a magnetic connector according tocertain teachings of the present disclosure having an electromagnet andswitch element.

FIG. 15 illustrates an embodiment of a magnetic connector according tocertain teachings of the present disclosure having an electromagnet anda proximity sensor.

FIG. 16 illustrates an embodiment of a magnetic connector according tocertain teachings of the present disclosure having an electromagnet andfault detector.

FIG. 17 illustrates an embodiment of a magnetic connector according tocertain teachings of the present disclosure having two electromagnetsand fault detector.

FIG. 18 illustrates an embodiment of a magnetic connector according tocertain teachings of the present disclosure having an electromagnet andcontrol circuitry.

While the disclosed magnetic connectors are susceptible to variousmodifications and alternative forms, specific embodiments thereof havebeen shown by way of example in the drawings and are herein described indetail. The figures and written description are not intended to limitthe scope of the inventive concepts in any manner. Rather, the figuresand written description are provided to illustrate the inventiveconcepts to a person skilled in the art by reference to particularembodiments, as required by 35 U.S.C. §112.

DETAILED DESCRIPTION

Referring to FIG. 3, an embodiment of a magnetic connector 100 accordingto certain teachings of the present disclosure is illustrated in across-sectional view. The magnetic connector 100 includes a firstconnector or plug 110 and a second connector or receptacle 150. The plug110 is connectable to a first device or electrical relation 50, whilethe receptacle 150 is connectable to a second device 60. In oneembodiment, the first device 50 is a transformer, and the second device60 is an electronic device, such as a laptop computer, having a housing62 and internal electronics 64. Therefore, in one embodiment, themagnetic connector 100 can be part of a power adapter for connecting thelaptop computer 60 to a conventional AC power supply (not shown) withthe transformer 50. For a standard laptop computer, the magneticconnector 100 is preferably rated for 6 A at 24V, and the plug 110 andreceptacle 150 can both be approximately 4-mm tall and 6-mm wide.

The plug 110 includes a plug body 112 having a face 118 and connected toa cable 114. Preferably, the body 112 is composed of a conventionalnon-conductive material. The body 112 houses internal wires 116 of thecable 114, which connects to the first device 50. A plurality of firstelectrical contacts 120 and a first magnetic element 130 are positionedon the plug body 112. In a preferred embodiment and as shown in FIG. 3,the first electrical contacts 120 are preferably plated and springloaded pins to maintain contact with the corresponding contacts on thereceptacle 150. The pins 120 are held in housings 124 and are connectedto the wires 116 of the cable 114. Springs 122 bias the pins 120 so thatthey extend from the face 118 of the plug body 112. In the presentembodiment, the first magnetic element 130 is embedded in the face 118of the plug body 112.

The receptacle 150 has a body 152 connected to the housing 62 of thesecond device 60. The body 152 has a face 158, a plurality of secondelectrical contacts 160, and a second magnetic element 140. In apreferred embodiment and as shown in FIG. 3, the second electricalcontacts 160 are plates embedded in the face 158 of the body 152 andelectrically connected to the internal electronics 64 by wires 162 orthe like. In addition, the second magnetic element 170 is embedded inthe face 118 of the body 152.

To make the electrical connection between the first and second devices50 and 60, the face 118 of the plug 110 is positioned against the face158 of the receptacle 150. The pins 120 on the plug 110 engage theplates 160 on the receptacle 150. Thus, the wires 116 connected to thefirst device 50 are electrically connected to the wires 162 connectingto the internal electronics 64 of the second device 60. As will beappreciated by one skilled in the art, electrical connection betweenpointed pins 120 and substantially flat plates 160 is preferred for anumber of reasons, such as issues related to Hertzian stresses around acontact point and issues related to contact asperities or aspots.

To maintain the electrical connection, the attractive force between thefirst and second magnetic elements 130 and 170 holds the plug 110 to thereceptacle 150. In one embodiment, both magnetic elements 130 and 170are magnets, either permanent or electromagnetic, arranged to attractmagnetically to one another. In an alternative embodiment, eithermagnetic element 130 or 170 is a magnet, either permanent orelectromagnetic, while the other complementary element is aferromagnetic material. The permanent magnet used for the magneticelements is preferably a permanent rare earth magnet because rare earthmagnets have a high flux density compared to their size. When the plug110 and receptacle 150 are brought into proximity, the attractive forcebetween the magnetic elements 130 and 170 maintains the contacts 120 and160 in an electrically conductive relationship.

The magnetic attraction or force of the plug 110 coupled to thereceptacle 150 can be configured for a particular implementation asdesired. For embodiments of the magnetic connector 100 used for a poweradapter, the magnetic field produced by the magnetic attraction betweenthe elements 130 and 170 is small enough not to interfere with thesupply of power through the electrical contacts 120 and 160. Becausemagnetic fields of the elements 130 and 170 may interfere with theinternal electronics 64 and other components of the device 60, thereceptacle 150 may be positioned on the housing 150 at a location awayfrom various components. For example, the receptacle 150 may bepositioned away from disk drives, USB ports, internal busses, etc. of alaptop computer. Alternatively, the elements 130 and 170 may be shieldedfrom various components of the electronic device, or a flux bar may beused to direct any magnetic flux of the elements 130 and 170 away fromvarious components.

In one embodiment shown in the front view of FIG. 4, the receptacle 150has four electrical plates 160 positioned around the centrally locatedmagnetic element 170. The body 152 of the receptacle is oval or oblongand has two axes of symmetry. For the embodiment of the receptacle 150requiring DC power, two of the electrical plates 160(+) may be positivecontacts, and two of the plates 120(−) may be negative contacts. Variousarrangements are possible and would be within the abilities on oneskilled in the art.

In the embodiment shown in the front view of FIG. 5, the plug 110 ismade to correspond with the arrangement of the receptacle 150 in FIG. 4.Therefore, the body 112 of the plug 110 is also oval, and the plug hasfour pins 120 positioned around the magnetic element 130, which iscentrally located on the plug 110. For the embodiment of the plug 110connected to an AC to DC transformer, two of the electrical contacts120(+) are positive contacts, and two of the contacts 120(−) arenegative contacts.

The arrangement of the pins 120 and plates 160 is symmetrical along theaxes of symmetry defined by the oval or oblong shape of the bodies 112and 152. In this way, the plug 110 and receptacle 150 can be coupled inonly two ways, and proper alignment of positive pins 120(+) withpositive plates 160(+) and of negative pins 120(−) with negative plates160(−) will be ensured. Although the plug 110 and receptacle 150 areshown having one magnetic element 130 and 170 each, it will beappreciated that each can include one or more magnetic elements. Inaddition, it will be appreciated that the plug 110 and receptacle 150can each have one or more contacts, depending on the type of electricalconnection to be made. For example, additional pins and contacts may besymmetrically arranged around the plug 110 and receptacle 150 forpassing electrical signals between two devices, such as a laptopcomputer and power adapter.

Referring to FIG. 6, an ability of the magnetic connector 100 to preventpossible damage is illustrated. The magnetic connector 100 substantiallyavoids damage because male components are not required to have aninterference fit with female components to maintain both electrical andmechanical connection. Instead, a user of the connector 100 needs onlyto position the faces 118 and 158 of the plug 110 and receptacle 150against or away from one another when making or releasing the electricaland magnetic connection therebetween. Being biased towards plates 160,the pins 120 can avoid damage while still maintaining contact with theplates 160. In addition, the magnetic connector 100 can substantiallyavoid damage by allowing the plug 110 and receptacle 150 to break freeof one another when inadvertently pulled away from each other by anon-axial force. Although shown slightly recessed in the device 60, theface 158 of the receptacle 150 can also be flush with the housing or canprotrude therefrom. However, the recess is used to prevent straymagnetic fields from interfering with other devices.

Referring to FIG. 7, another embodiment of a magnetic connector 200according to certain teachings of the present disclosure is illustrated.This embodiment is substantially similar to the embodiment of FIGS. 3through 5 so that like reference numbers indicate similar components. Incontrast to previous embodiments, the receptacle 250 in this embodimentis not housed in a device (not shown) to which it is connected as withprevious embodiments. Rather, the receptacle 250 resembles the plug 110in that it has a body 252 that connects to the device with a cable 254.In addition, the bodies 112 and 252 of the plug 110 and receptacle 150are substantially round. To ensure proper alignment of the pins 120 withthe plates 160, the plug 10 and receptacle 150 have complementary guides119 and 159 that allow for only one way of coupling them together.Although the guides 119 and 159 are shown on the faces 118 and 158 ofthe plug 110 and receptacle 150, it will be appreciated by one skilledin the art that a number of guides and techniques can be used to ensureproper alignment.

Referring to FIGS. 8A-8B and 9A-9B, another embodiment of a magneticconnector according to certain teachings of the present disclosure isillustrated. A first connector or plug 310 of the magnetic connector isshown in a partial side cross-section and in a front view of FIGS.8A-8B. A second connector or receptacle 350 of the magnetic connector isshown in a partial side cross-section and in a front view of FIGS.9A-9B. Both the plug 310 and receptacle 350 can be at least partiallycomposed of transparent, non-conductive material and can includeinternal lights, such as LEDs, to illuminate them.

As shown in FIGS. 8A-8B, the plug 310 includes a body 312, a pluralityof pins 320, and a first magnetic element 330, and a shell 340. The body312 is made of any suitable non-conductive material and has an oblongshape with two axes of symmetry A₁ and A₂. The body 312 houses internalwires 316 of a cable 314, which connect the pins 320 to a first device(not shown), such as a transformer, for example. The pins 320 are biasedby springs, and the pins 320 extend from a face 318, which is slightlyrecessed in the plug body 312. The first magnetic element 330 ispositioned on the end of the plug body 312. As best shown in FIG. 8B,the first magnetic element 330 surrounds the recessed face 318 of thebody 318.

For the embodiment of the plug 310 connected to a transformer, thecentrally located pin 320 can be designated for signals used by theelectronic device to determine the type of transformer or other deviceattached by the plug 310. The two outer located pins 320 can bedesignated for the positive DC power, and the outer shell 340 isdesignated for the return path of DC power. In this way, any orientationof the plug 310 will ensure proper connection of positive pins 320(+)and signal pin 320(S) of the plug 310 with corresponding contacts of thereceptacle (350; FIGS. 9A-9B). Using the outer shell 340 for the returnpath is preferred because the plug 310 can have a smaller profile. In analternative embodiment, however, the return path can be provided byadditional pins (not shown) on the plug 310 and receptacle 350. Forexample, two additional pins (not shown) for the additional return pathcould be provided and symmetrically arranged on the plug 310 such thatthe pins would only align with corresponding contacts (not shown) of thereceptacle 350 regardless of the orientation in which the plug 310 iscoupled to the receptacle 350.

As shown in FIGS. 9A-9B, the receptacle 350 has a body 352, a pluralityof contacts 360, and a second magnetic element 370, and a shell 380. Thebody 352 has a casing 356 with legs 357 for mechanical connection to aprinted circuit board of internal electronics of a second device (notshown), such as a laptop computer, for example. The casing 356 can becomposed of a conductive or non-conductive material. The body 352 has anoblong shape with two axes of symmetry A₁ and A₂ and is made of anysuitable non-conductive material. As best shown in FIG. 9B, the body 352also has snap connectors 359 for mechanical connection to a mountingbase (not shown). In addition, the receptacle 350 has pins 364 forconnecting the contacts 360 to internal electronics of the device.

The body 352 has an end 354 intended to extend outside the devicehousing the receptacle 350. This end 354 may be illuminated bytechniques known in the art. The contacts 360 are positioned in a face358 of the body 352. In the present embodiment, the contacts 360 aresubstantially flat plates electrically connected to the pins 364 bywires 362. The second magnetic element 370 is positioned about the face358, and the second magnetic element 370 is preferably recessed from theface 358. Preferably, the recess of the second magnetic element 370 isslight and is comparable to the recess of the face (318) of the plug(310) in FIG. 8A. For the embodiment of the receptacle 350 intended toconnect DC power to the device, the plates 360 are arranged tocorrespond with the positive pins (320(+)) and signal pin (320(S)) ofthe plug (310) of FIGS. 8A-8B, as described previously.

To make the electrical connection, the face 318 of the plug 310 of FIG.8A is positioned against the face 358 of the receptacle 350 of FIG. 9A.The pins 320 on the plug 310 engage the plates 360 on the receptacle350. To maintain the connection, the first and second magnetic elements330 and 370 magnetically couple together and hold the plug 310 to thereceptacle 350. In one embodiment, the magnetic elements 330 and 370 areboth permanent magnets (preferably rare earth magnets) arranged tomagnetically couple together. In another embodiment, one of the magneticelements 330 and 370 can be a permanent magnet (preferably a rare earthmagnet) or an electromagnet while the other element is a ferromagneticmaterial.

Once coupled, the magnetic connector 300 allows the plug 310 to breakaway from the receptacle 350 in the event of inadvertent pulling of theplug 310 or the like.

Referring to FIG. 10, additional details of the plug 310 and receptacle350 for the disclosed magnetic connector of FIGS. 8A-8B and 9A-9B areillustrated in a perspective view. Portions of the plug 310 andreceptacle 350 are not illustrated so that various details can be bettershown. On the plug 310, the shell 340 abuts the magnetic element 310,which can be a ferromagnetic material. The shell 340 has an extension342 for connecting to the return path of the power supply from theadapter (not shown) to which the plug 310 is connected. Three connectors322(+), 322(S), and 322(+) extend from the back end of the body 312 forconnecting the pins (not shown) with the positive power and signal fromadapter to which the plug 310 is connected.

On the receptacle 350, the shell 380 for the return path of the power ispositioned within the casing 356, and the magnetic element 370, whichcan be a permanent magnet, is positioned within the shell 380. Anopening 372 through the magnetic element 370 allows for passage of bodymaterial (not shown) and contacts (not shown), as disclosed previously.Tabs or holders 382 of the shell 380 contact and hold the magneticelement 370. A leg 384 of the shell 380 extends from the receptacle 350as do legs 357 of the casing 356.

When the plug 330 is coupled with the receptacle 350, the ferromagneticmaterial 330 of the plug 310 positions against the permanent magnet 370and the inside of the casing 380 of the receptacle 350. Thus, themagnetic engagement between the ferromagnetic material 330 and thepermanent magnet 370 holds the plug 310 to the receptacle. Moreover, thephysical engagement between the ferromagnetic material 330 and thecasing 380 creates the return path for power from the receptacle's shellpin 384 to the plug's shell pin 342.

Referring to FIGS. 11A-11B, an embodiment of a magnetic connector 360according to certain teachings of the present disclosure is illustrated.The connector 360 is compact and preferably has a low profile. In FIG.11A, a plug 370 of the connector 360 is shown in a front perspective. InFIG. 11B, some of the internal components of plug 370 and a receptacle390 are shown in a back perspective. The receptacle 390 is housed in anelectronic device (not shown), and the plug 370 attaches to a cord orthe like (not shown). As best shown in FIG. 11A, the plug 370 hasmagnets 380, 382 positioned on both sides of a plurality of contacts376, which are similar to other contacts disclosed herein. For example,the central contact 376 is designated for a first path of electricalcommunication, and the two outer contacts 376 are designated for asecond path of electrical communication. Preferably, the contacts 376are biased pins where the central pin 376 carries a signal path and thetwo side pins carry a positive current. The magnets 380, 382 arearranged with opposite polarities, as indicated by the direction of thearrows in FIG. 11A. Preferably, the magnets 380, 382 are also designatedfor a third path of electrical communication.

As best shown in FIG. 11B, the plug 370 also has a back plate 372connected between the back ends of the magnets 380, 382. The back plate372 is made of a ferromagnetic material, such as steel. The receptacle390 has an attraction plate 392 also made of a ferromagnetic material,such as steel. When the attraction plate 392 of receptacle 390 isattracted to the magnets 380, 382, the magnetic field lines travelthrough the steel attraction plate 392 from one magnet to the other,completing the magnetic circuit and producing a strong attracting force.

The attraction plate 392 of receptacle 390 defines an opening 394 forpassage of the electrical contacts (not shown in FIG. 11B). Likewise,the back plate 372 of the plug 370 defines openings 374 for passage ofleads from the electrical contacts (not shown). As noted above, themagnets 380, 382 can form a path of electrical communication between thereceptacle 390 and the plug 370. Preferably, the magnets 380 and 382 andthe attraction plate 392 carry negative current. Thus, the attractionplate 392 of the receptacle 390 includes a connector 396 for connectingto an electrical lead or the like (not shown).

Because the connector 360 is designed to be compact and have a lowprofile for fitting into a laptop or the like, the plates 372 and 392must give up a certain amount of material to produce the openings 374and 394. When the attraction plate 392 and magnets 380, 382 are coupled,magnetic attractive force can be limited because the flux density cansaturate the narrower portions of ferromagnetic material in both theattraction plate 392 and the back plate 374. (Therefore, it may bedesirable to use more than two magnets with the connector, as disclosedin the embodiment below). It may be desirable to have more than twomagnets within the connector for two reasons. First, magnetic strengthis a function of magnet thickness to cross section ratio (with thicknessbeing defined by the dimension along the direction of magnetization).Second, for a given envelop, the leakage field associated with more thantwo permanent magnets is less than the leakage field associated with oneor two permanent magnets.

Referring to FIGS. 12A-12B, another embodiment of a magnetic connector360 according to certain teachings of the present disclosure isillustrated. The magnetic connector 360 in FIGS. 12A-12B issubstantially similar to that disclosed above so those like numeralsindicate similar components between the embodiments. In the presentembodiment, however, the plug 370 houses four magnets 380, 381, 382, and383. Again, the magnets 380, 381, 382, and 383 are arranged withopposite polarities, as indicated by the arrows in FIG. 12A. In thepresent embodiment, the four magnets 380, 381, 382, and 383 form fourmagnetic circuits for the travel of magnetic flux. Accordingly, most ofthe flux travels between magnets on the same side (e.g., between magnets380, 381 on the same side and between magnets 382, 383 on the sameside). Because the flux lines are not constrained by the narrow portionsof the plates 372 and 392, the flux density is less likely to saturatethe plates 372 and 392. Therefore, the magnetic attractive force betweenthe receptacle 390 and the plug 370 having four magnets 380-384 can besignificantly greater than available in the embodiment of FIGS. 11A-11B,even though both embodiments have the same contact area.

As noted previously, the magnetic attraction or force coupling the plug370 and the receptacle 390 can be configured as desired for a givenimplementation. In one embodiment, a straight pullout force to uncouplethe plug 370 from the receptacle 390 is preferably between 3-lbf and7-lbf. It should be noted that pulling the plug 370 out sideways, up, ordown can produce torque. Preferably, the magnetic attraction producesless torque in the up direction but produces more torque in the otherdirections. Target torque values can be 0.5 kgf-cm for the up directionand 0.7 to 1.5 kgf-cm in the other directions.

In one aspect, the asymmetrical torque values can be achieved byextending the upper magnets 380 and 382 upwards. In this way, the uppermagnets 380 and 382 are stronger and provide more attraction upwardsthan the lower magnets 381 and 383. One resulting effect is that therecan be more holding force and displacement of the application point ofthe force upward, subsequently leading to more torque. This also helpscompensate for any downward torque that may be produced by a cable (notshown) coupled to the plug 370. In another aspect, the asymmetricaltorque values can be achieved by changing the angle of the magnetic fluxlines in the upper magnets 380 and 382. For example, the separate, uppermagnets 380 and 382 can have flux direction that point downward at anapproximately 20-degree angle in comparison to the direction ofcoupling.

Referring to FIG. 13A, an embodiment of a magnetic connector 400 havingan electromagnet is illustrated. The connector 400 includes a plug 410and a receptacle 450. The plug 410 is not substantially different fromthat disclosed in the embodiment of FIG. 8A-8B. The plug 410 hascontacts 420 for conveying power from a transformer (not shown) and hasa magnetic element 430, which can be a ferromagnetic material. Thereceptacle 450 has contacts 460 for conveying power to internalelectronics 76 of the device 70, which is a laptop computer in thepresent embodiment.

In contrast to previous embodiments, the receptacle 450 has anelectromagnet formed by a metal core 470 wrapped by a wire coil 472.Using an electromagnet in the plug 410 or receptacle 450 can overcomesome of the disadvantages of having a permanent magnet on either theplug 410 or receptacle 450. For example, the electromagnet may reducepotential interference with internal components of the electronic device70 or storage media.

The coil 472 is connected to a power supply or battery 72 of the laptop70, and an internal switch 74 among other electronics can be used tooperate the electromagnet of the core 470 and coil 472. The internalswitch 74 causes power from the battery 72 to energized theelectromagnet of core 470 and coil 472. Consequently, the energizedelectromagnet produces a magnetic field that attracts the ferromagneticmaterial 430 of the plug 410 and that can hold the plug 410 to thereceptacle 450. The battery 72 can be an independent battery of thedevice or can be the same battery used to power the internal electronics76 of the device 70. In either case, operation of the internal switch 74and other electronics for connecting the battery 72 to theelectromagnetic is preferably controlled to conserve power consumptionof the battery 72.

Referring to FIG. 13B, another embodiment of a magnetic connector 500having an electromagnet is illustrated. The connector 500 includes aplug 510 and a receptacle 550. The receptacle 550 is not substantiallydifferent from that disclosed in the embodiment of FIG. 9A-9B. Thereceptacle 550 has contacts 560 for conveying power and signals tointernal electronics 76 of the device 70. The receptacle 550 also has amagnetic element 570, which can be a ferromagnetic material. The plug510 has contacts 520 for conveying power and signals from a powersupply, such as power adapter 80, via wires 522 of a cable 86. Incontrast to previous embodiments, the plug 510 has an electromagnetformed by a metal core 530 wrapped by a wire coil 532. The coil 532 isconnected to a power supply by wires 534. For example, the coil 532 candraw power output from the transformer 82 of the adapter 80, form aconventional power supply to which the outlet plug 88 connects, or froma battery 84 housed internally in the adapter 80. Use of the battery 84can overcome the need for a user to first connect the adapter 80 to thepower supply before the electromagnet in the plug 510 is operated andcan magnetically connect to the receptacle 550. The drawn powerenergizes the electromagnet of core 530 and coil 532 to produce amagnetic attraction to the ferromagnetic material 570 that can hold theplug 510 to the receptacle 550.

Referring to FIG. 14, an embodiment of a magnetic connector 600according to certain teachings of the present disclosure is illustrated.The connector 600 has a plug 602 having contacts 604 and anelectromagnet 606. The connector 600 also has a receptacle 620positioned on a portable computer or electronic device 630. Thereceptacle 620 has an attraction plate or magnet 622 and contacts 624.The contacts 624 act as paths for electrical communication so that theyare electrically coupled to internal electronics 632 of electronicdevice 630. In addition, the attraction plate or magnet 622 acts as apath of electrical communication so that it is also electrically coupledto the internal electronics 632. In the schematic view of FIG. 14,various components, such as leads, contacts, and coils, are not shownfor simplicity.

In the present embodiment, the electromagnet 606 is in the plug 602;however, it can be positioned in the receptacle 620. The electromagnet606 derives its power from circuitry 612 of the power adapter 608 so theelectromagnet 606 does not drain a battery (not shown) of the electronicdevice 630. In the present embodiment, the plug 602 includes a switchelement 610 interrupting the electrical connection between theelectromagnet 606 and the circuitry 612 of the adapter 608.

In one embodiment, the switch element 610 includes a mechanical switchthat a user presses to turn the electromagnet 602 on and off. Anymechanical switch, such as a conventional micro-switch, for controllingthe power load of the electromagnet 602 is suitable for the connector600. In general, the switch element 610 allows the electromagnet 606 torun directly from power of the adapter 608.

In another embodiment, the switch element 610 includes a touch sensorthat energizes (e.g., turns on) the electromagnet 606 when a usertouches the sensor 610 by picking up the plug 602. Touch sensors areknown in the art. For example, the touch sensor 610 can include logiccircuitry and contacts (not shown) and can use principals of capacitanceof the human body for operation. Once activated by the touch sensor 610,the electromagnet 606 can remain energized for a time interval to allowthe user to couple the plug 602 to the receptacle 620 and to turn on theelectronic device 630. Once the energized electromagnet 606 ismagnetically coupled to the attraction plate 622 of the receptacle 650,the contacts 604 and 624 that form a signal path between the adapter 608and the device 630, and a signal along the signal path can be used tokeep the touch sensor 610 activated and the electromagnet 606 energized.

While the plug 602 is connected and the electromagnet 606 energized, thetouch sensor 610 can turn off the electromagnet 606 when touched toallow the user to disconnect the plug 602. Alternatively, the touchsensor 610 can reduce the energization of the electromagnet 606 toenable easy removal by the user but to keep a small remainingattraction. In addition, when the device 630 is turned off, the device630 may no longer send a signal along the signal path of the contacts604 and 624 or may send a quit signal to the touch sensor 610 to stopenergization of the electromagnet 606. Then, the de-energizedelectromagnet 606 can allow the plug 602 to be released from theelectronic device 630.

In yet another embodiment, the switch element 610 includes a motionsensor, which detects when the plug 602 is moved. The motion sensor 610can maintain the electromagnet 606 energized for a time interval toallow the user to couple the plug 602 with the receptacle 620 and toturn on the electronic device 630. Once coupled, the signal path formedby contacts 604 and 624 can allow a signal to control the circuitry ofthe motions sensor 610 to maintain it activated while coupled to thedevice 630. The motion sensor 610 can automatically shut off theelectromagnet 606 so as to release the plug 602 from the device 630 if asudden movement occurs (e.g., the device 630 is dropped or pulled awaywith the plug 602 connected).

Referring to FIG. 15, an embodiment of a magnetic connector 600according to certain teachings of the present disclosure is illustratedhaving an electromagnet 606 and a proximity sensor 640. Referencenumerals in FIG. 15 that are the same as those in other Figuresrepresent like components between embodiments. The proximity sensor 640is positioned in the plug 602 and is coupled to a switch element 642.The electromagnet 606 is also coupled to the switch element 642, whichin turn is coupled to circuitry 644 for providing power located in theadapter 608. The proximity sensor 640 and switch element 642 turn on theelectromagnet 606 when the sensor 640 is positioned near plate 622 ofthe receptacle 620.

In one embodiment, the proximity sensor 640 includes a Hall Effectsensor, which detects magnetic field levels. In use, the electromagnet606 is initially energized before being coupled to the receptacle 620.The initial energization can be achieved, for example, when the adapter608 is coupled to a power source (not shown) or when a touch sensor (notshown) or the like is activated by the user. The initial energizationcan be less than that necessary to magnetically couple the electromagnet606 to the plate 622. Once the plug 602 is moved in proximity to thereceptacle 622, the magnetic field associated with the initialenergization of the electromagnet 606 is changed, which is subsequentlydetected by the Hall Effect sensor 640. The sensor 640, in turn, causesthe energization of the electromagnet 606 to be increased to allow it tomagnetically couple to the attraction plate 622.

Referring to FIG. 16, an embodiment of a magnetic connector 600according to certain teachings of the present disclosure is illustratedhaving an electromagnet 606 and fault detection circuitry 650. Referencenumerals in FIG. 16 that are the same as those in other Figuresrepresent like components between embodiments. As before, theelectromagnet 606 is energized to magnetically couple with theattraction plate 626 of receptacle 620, which can be ferromagneticmaterial or a permanent magnet. The fault detection circuitry 650detects a fault event caused, for example, by a surge or spike in thepower supply.

The fault detection circuitry 650 can be similar to that commonly usedin the art for power adapters. In one embodiment, for example, the faultdetection circuitry 650 can include circuitry for detecting anover-current. In another embodiment, for example, the fault detectioncircuitry 650 can include circuitry for detecting an over-temperature.

When the fault detection circuitry 650 detects a fault event, thecircuitry 650 can stop energizing the electromagnet 606 and allow theplug 602 to be released from the embodiment of the receptacle 620 havinga ferromagnetic attraction plate 626. Alternatively, the circuitry 650can reverse the direction of current supplied through the electromagnet606 so the electromagnet 606 is repelled by the polarity of theembodiment of the receptacle 620 having a permanent magnet on theattraction plate 626. It will be appreciated that the electromagnet 606and fault circuitry 650 can be positioned on the device 630 while theattraction plate can be positioned on the plug 602 of the connector 600to achieve the same protection.

Referring to FIG. 17, an embodiment of a magnetic connector 600according to certain teachings of the present disclosure is illustratedhaving two electromagnets 606 and 660. The plug 602 has the firstelectromagnet 606, which is energized by the power adapter 608. Thereceptacle 620 positioned in the device 630 has the second electromagnet660, which is power by an internal power supply 662, such as a battery.The two electromagnets 606 and 660 have opposite polarities allowingthem to be magnetically coupled.

In one embodiment, the adapter 608 includes fault detection circuitry650. When a fault is detected by fault detection circuitry 662, thepolarity of the first electromagnet 606 can be reversed by the circuitry650 so that the first and second electromagnets 606 and 660 repel oneanother and actively prevent connection.

In another embodiment, the adapter 608 includes circuitry 650 foridentifying the adapter 608. For example, the identification circuitry650 can identify a type of electronic device to which it is intended tobe connected or can even identify a specific device to which is can onlybe used. When a user intends to connect the plug 602 to the receptacle620, the first electromagnet 606 can be energized according to thetechniques disclosed herein. However, the second electromagnet 660 canremain de-energized. When the user positions the plug 602 against thereceptacle 620, the signal path formed by contacts 604 and 624 allow theidentification circuitry 650 to send a signal to the internalelectronics 632 of the device, which can identify the adapter 608 beingconnected to the device 630.

If the adapter 608 is intended for the device 630, then the secondelectromagnet 660 can be energized with opposite polarity to couple withthe first electromagnet 606, or the second electromagnet 660 can remainde-energized while the first electromagnet 606 is simply allowed tomagnetically couple with the ferromagnetic components of thede-energized electromagnet 660. If, on the other hand, the adapter 608is not intended for the device 630, then the second electromagnet 660can be energized with the same polarity to repel the first electromagnet606 and actively prevent connection.

Referring to FIG. 18, an embodiment of a magnetic connector 600according to certain teachings of the present disclosure is illustratedhaving an electromagnet 606 and control circuitry 670. In oneembodiment, the control circuitry 670 includes a switch element, whichreceives a control signal from the internal electronics 632 of thedevice 630. When the battery of the electronic device 630 is fullycharged, the internal electronics 632 sends a control signal to thecontrol circuitry 670 via the signal path formed by contacts 604 and624. Moreover, when the internal electronics 632 detects a fault, it cansend a control signal to the control circuitry 670.

As described above, one of the contacts 604 on the plug 602 and one ofthe contracts 624 on the receptacle 620 (preferably, the centrallylocated contacts 604 and 624) can form a signal path between the device630 and the adapter 608. It is along such a signal path that the controlsignal indicating the fully charged battery is sent. When the signal for“full charge” is received, the control circuitry 670 causes its internalswitch element to stop energization of the electromagnet 606, and theplug 602 becomes decoupled from the receptacle 626. If it is desirableto keep the plug 602 magnetically coupled, albeit slightly, to thereceptacle 620 even after full charging of the battery, the plate 627 onthe receptacle 620 can include a magnet (not shown) for maintaining atleast some magnetic coupling with ferromagnetic material of theelectromagnet 606.

In another embodiment, the control circuitry 670 receives a controlsignal, which governs whether the adapter 608 associated with thecontrol circuitry 670 can operate with the electronic device 630. Inthis embodiment, the internal electronics 632 on the device 630 producesa control signal that identifies the device 630, such as by its make ormodel. The control signal can be a digital signal, for example,identifying the device 630. The control circuitry 670 in the adapter 608is pre-configured to energize the electromagnet 606 only when theidentifying control signal is received. To respond to the controlsignal, the control circuitry includes a switch element for controllingthe electrical connection of the electromagnet 606 with its energizingsource, and the circuitry includes a logic element for interpreting thecontrol signal and activating the switch element.

Thus, when a user positions the plug 602 against the receptacle 620 toconnect them, the signal contacts 604 and 624 on the plug and receptacle602 and 620 will make contact, allowing the internal electronics 632 ofthe device 630 to communicate its identifying control signal to thecontrol circuitry 670 of the adapter 608. If the circuitry 670 receivesthe correct signal, an internal switch within the circuitry causes theelectromagnet 606 to be energized for coupling with the receptacle.Otherwise, the electromagnet will not be energized, and the plug 602will not stay coupled to the receptacle 620.

Accordingly, the electromagnet 606 on the adapter 608 will only beenergized for a particular model or type of device, which may preventthe possibility of a user inadvertently coupling an adapter with aspecific power rating to a device requiring a different power rating.

For example, harm to a computer can be prevented because the computerwill not allowing itself to be connected to the wrong type of poweradapter (e.g., one that supplies a higher voltage than the computer'sspecification). Furthermore, the control circuitry 670 andidentification of the device 630 can be configured so that the device630 will only draw power only from a particular power adapter or a groupof power adapters. Such a configuration can be useful in varioussettings, such as a school or other public organization, to discouragetheft.

In yet another embodiment, the control circuitry 670 includes a securitysystem, which requires the user to enter a particular code or otheridentification. Without the entered code, the control circuitry 670 willnot energize the electromagnet, and the plug 602 will not engage withthe receptacle 620.

In the present disclosure, embodiments of magnetic connectors have beendisclosed in the context of providing power from a transformer to alaptop computer. However, it will be appreciated with the benefit of thepresent disclosure that the subject matter of the present disclosure isapplicable to various types of connectors, which provide electricalconnection in the form of power and/or signals between an electronicdevice and any of a number of electronic devices or electricalrelations. For example, other applicable electronic devices orelectrical relations include portable DVD players, CD players, radios,printers, portable memory devices, portable disk drives, input/outputdevices, power sources, batteries, etc. Other applicable types ofelectrical connections that can be provided by the connectors of thepresent disclosure include Universal Serial Bus, D-subminiature,FireWire, network connectors, docking connectors, etc.

In the present disclosure, a number of embodiments of magneticallycoupleable connectors are disclosed. With the benefit of the presentdisclosure, it will be appreciated that aspects or features of oneembodiment disclosed herein can be used in or combined with aspects andfeatures of other embodiments disclosed herein to produce additionalembodiments consistent with the teachings of the present disclosure.

The foregoing description of preferred and other embodiments is notintended to limit or restrict the scope or applicability of theinventive concepts conceived of by the Applicants. In exchange fordisclosing the inventive concepts contained herein, the Applicantsdesire all patent rights afforded by the appended claims. Therefore, itis intended that the appended claims include all modifications andalterations to the full extent that they come within the scope of thefollowing claims or the equivalents thereof.

1. A connector receptacle comprising: a recessed portion having anoblong shape, the oblong shape having a longer first axis and a shortersecond axis, the recessed portion further having a bottom surface andsidewalls substantially orthogonal to the bottom surface; at least threecontact pins located in the recessed portion, extending above the bottomsurface of the recessed portion, and not extending above a top of thesidewalls of the recessed portion, the at least three contacts to conveypower and a return path, the at least three contacts arrangedsubstantially in a line along the first axis; and a first magnetpositioned under the bottom surface of the recessed portion, and towardsa first end of the first axis; and a second magnet positioned under thebottom surface of the recessed portion, and towards a second end of thefirst axis, the first magnet and the second magnet having opposingpolarities, wherein the recessed portion and the at least three contactsare arranged such that the connector receptacle is at leastsubstantially symmetrical along the first axis and the second axis. 2.The connector receptacle of claim 1 wherein the recessed portion has anoblong shape.
 3. The connector receptacle of claim 1 wherein two of theat least three contacts are used as a return path.
 4. The connectorreceptacle of claim 1 wherein the recessed portion has two long sidesthat are substantially straight and two shorter sides that are rounded.5. The connector receptacle of claim 1 wherein the three contacts have asubstantially bowled top surface.
 6. The connector receptacle of claim 1wherein the first magnet and the second magnet are positioned next toeach other along the first axis.
 7. The connector receptacle of claim 1wherein the bottom surface is substantially flat.
 8. The connectorreceptacle of claim 1 wherein the first magnet and the second magnet arerare-earth magnets.
 9. A connector receptacle comprising: a bottomsurface having two opposing straight sides and two opposing curvedsides, the two opposing curved sides at a first end and a second end ofthe connector receptacle; a sidewall surrounding the bottom portion andsubstantially orthogonal to the bottom portion; three contacts, eachextending above the bottom surface and not above a top of the sidewall,the three contacts to form power and ground paths and arranged in asubstantially straight line parallel to the two opposing straight sidesof the bottom surface; a first magnet under the bottom surface of theconnector receptacle and towards the first end of the connectorreceptacle; and a second magnet under the bottom surface of theconnector receptacle and towards the second end of the connectorreceptacle, the first magnet and the second magnet having opposingpolarities.
 10. The connector receptacle of claim 9 wherein theconnector receptacle comprises exactly three contacts.
 11. The connectorreceptacle of claim 9 wherein the bottom surface and the three contactsare arranged such that the connector receptacle is at leastsubstantially symmetrical along a first axis and a second axis.
 12. Theconnector receptacle of claim 11 wherein the first axis and the secondaxis are orthogonal to each other.
 13. The connector receptacle of claim9 wherein two of the three contacts are used as a return path.
 14. Theconnector receptacle of claim 9 wherein the first magnet and the secondmagnet are rare-earth magnets.
 15. The connector receptacle of claim 9wherein the bottom surface is substantially flat.
 16. A connectorreceptacle comprising: a recessed portion defined by a bottom surfacehaving two opposing straight sides and two opposing curved sides, thetwo opposing curved sides at a first end and a second end of theconnector receptacle, and a sidewall surrounding the bottom portion andsubstantially orthogonal to the bottom portion, three contacts, eachextending above the bottom surface and not above a top of the sidewall,the three contacts arranged to mate with contacts in a connector insertand to form power and ground paths, the three contacts arranged in asubstantially straight line; a first magnet under the bottom surface ofthe connector receptacle and towards the first end of the connectorreceptacle; and a second magnet under the bottom surface of theconnector receptacle and towards the second end of the connectorreceptacle, the first magnet and the second magnet having opposingpolarities such that when the connector insert is brought in closeproximity to the connector receptacle, magnetic field lines travelthrough a magnetic element of the connector insert from the first magnetin the connector receptacle to the second magnet in the connectorreceptacle.
 17. The connector receptacle of claim 16 wherein anattraction between the magnetic element in the connector insert and thefirst and second magnets in the connector receptacle hold the connectorinsert and the connector receptacle together in a first direction, andthe recessed portion of the connector receptacle is arranged to hold theconnector insert and the connector receptacle together in a seconddirection and a third direction.
 18. The connector receptacle of claim17 wherein the recessed portion of the connector receptacle is arrangedto hold the connector insert without requiring an interference fit. 19.The connector receptacle of claim 17 wherein the connector insert may beremoved from the connector receptacle with a non-axial force.
 20. Theconnector receptacle of claim 16 wherein the connector insert and theconnector receptacle may be mated in one of at least two orientations.21. The connector receptacle of claim 16 wherein the recessed portion isarranged to accept the connector insert in at least two orientations.22. The connector receptacle of claim 16 wherein the three contacts arearranged in a substantially straight line parallel to the two opposingstraight sides of the bottom surface.